The invention relates to the technical field of producing and
machining of gun steel products, in particular to a heat treatment method of an SLM molding gun steel product. The heat treatment method includes the following steps of firstly,
coating the surface of the SLM molding gun steel product with a layer of high-temperature-resistant anti-oxidizing paint, then putting the gun steel product into a vacuum
atmosphere furnace, vacuumizing the furnace until the vacuum degree is 0.1-0.2 MPa, and injecting
argon with the purity of 99% or above until the vacuum degree is increased to 0.01-0.02 MPa; secondly, performing preheating; thirdly, performing
quenching treatment; fourthly, rapidly cooling SLM molding gun steel through an air conditioner; and fifthly, performing
tempering treatment, wherein the SLM molding gun steel product is put into the vacuum
atmosphere furnace again, the temperature is gradually raised to 540 DEG C from the original 0 DEG C, and the temperature is raised at therate of 30 DEG C per minute. The
anisotropy of mechanical performance of the SLM molding gun steel product is eliminated, the
toughness is improved, the
internal stress is reduced, the comprehensivemechanical performance of the SLM molding gun steel product is strong, meanwhile conventional devices are adopted in the process, the technological process is simple, operation is simple, and
batch production can be easily formed.